Archives are file systems and documents that are stored in persistent storage systems. Persistent storage systems include fixed optical or magnetic drives, flash memory devices, and removable storage devices such as read-write compact discs (RW-CDs) drives and magnetic tape drives. These archives are enciphered to secure the contents of the drive by limiting access to the contents of the archive to a user supplying a correct password.
The enciphering process that creates or adds to an archive requests a password from a user. The password is then input into a hashing algorithm to produce a key. The key is utilized to encipher the entire archive using a block cipher algorithm. However, this system presents several security and logistical problems. If the same password is used for multiple archives, then the same key is generated for each archive. Determining a key that is utilized to encipher data is made easier when a larger set of enciphered data is available. Thus, using the same key for multiple archives is not desirable, because it creates a large data set that is more vulnerable to unauthorized access.
Another problem with the use of this method and system is that the change of a password requires that the entire archive be re-enciphered using a new key generated from the new password. Archives can be large and re-enciphering these archives can be time consuming and inconvenient. All archives enciphered with a changed key must be deciphered and then re-enciphered with a new key. Also, archives can be distributed over multiple volumes, which can be on seperate devices or discs. As a result, the changing of the password can be very time and resource consuming especially for large archives or archives with multiple volumes.